9:12 AM Abstract No. 184 - Inferior vena cava (IVC) filter position and its effect on the incidence of deep venous thrombosis

Abstract

Purpose Inferior vena cava (IVC) filters are placed in patients with risk of venous thromboembolism (VTE) when chemical anticoagulation is not feasible or sufficient. However it has been demonstrated that IVC filters can actually increase the risk of VTE. Most filters are placed in an infrarenal location but there are no studies that explore whether the location of filter placement has an effect on the risk of a DVT. The purpose of this study was to determine whether IVC filter position can affect the risk of development of a DVT. Materials and Methods Patients who had IVC filters placed at the University of Michigan from January 1, 2005 to January 1, 2012 were identified. Filter position and other relevant data including potential risk factors for VTE were abstracted. Then their histories were used in order to determine whether they experienced deep venous thrombosis (DVT) after filter placement. Results Rates of thrombosis were 35/189 (18.5%) infrarenal compared to 6/62 (9.7%) suprarenal position and 13/129 (10.1%) when the filter tip was placed at the renal veins. Postoperative state was found to be protective of thrombosis (hazard ratio = 0.28; p Conclusion The position of IVC filters may affect patient outcomes, with infrarenal filters carrying a greater risk of DVT. Contrary to previous studies, postoperative state is protective of thrombosis. This may be due to greater attention to DVT prophylaxis in surgical patients.